Magnetic modulation to construct MXene/CNT@Fe3O4 electrodes with 3D conductive structures for ionic artificial muscles

Electrochemical ionic actuators have garnered significant attention following their discovery due to their potential to supplement or replace conventional rigid actuators, owing to their ability to achieve precise control over bending displacement across a wide range. This paper employs an MXene/CNT@Fe3O4 electrode in electrochemical ionic actuators, which consists of a three-dimensional conductive network comprising a one-dimensional carbon nanotube loaded with ferroferric oxide magnetic particles (CNT@Fe3O4) and a two-dimensional Ti3C2Tx MXene. This actuator is characterized by high bending displacement (12.3 mm), a comprehensive response range (0.1–10 Hz), fast response time (≈5 s), and excellent durability (5 h, 93% actuation retention). The exceptional characteristics mentioned above can be attributed to manipulating the CNT@Fe3O4 distribution within the MXene layers using magnetic regulation. This approach enhances dispersion and facilitates the formation of a three-dimensional conductive network structure with MXene, enabling efficient and multi-directional ionic migration. Moreover, the artificial muscles have successfully replicated flytraps' predation and birds' claw grasping. This study presents a new idea for the electrode design of electrochemical ionic actuators, elucidating the significant potential of MXene-based soft actuators in the domains of artificial muscles and bionics.